A Costly and Dangerous Global Phenomenon

In the United States, sexually active teens experience high rates of sexually transmitted infections (STIs), and some populations of youth face excessive risk—African American youth, young women, abused youth, homeless youth, young men who have sex with men (YMSM), and gay, lesbian, bisexual, and transgender (GLBT) youth. The STI epidemic is a global phenomenon, and wherever they live, youth in high risk situations also face a heightened risk of STIs.

Rates in the United States Are High among Teens and Young Adults.

From 1989 through 2008, reported chlamydia rates rose from 102.5 to 401.3 cases per 100,000 population in the United States, an increase attributed, at least partly, to improved screening and reporting.[1]

The highest age-specific chlamydia rates occurred among women ages 15 to 19 and 20 to 24 (3,275.8 and 3,179.9 per 100,000 women, respectively).[1]

Chlamydia rates among U.S. males, while considerably lower than among young women, were also highest in 15- to 19-year-old and 20- to 24-year-old men (701.6 and 1,056.1 per 100,000 men, respectively).[1]

Among women, gonorrhea rates were highest among those ages 15 to 19 and 20 to 24 (636.8 and 608.6 per 100,000 women, respectively); and among men gonorrhea rates were highest among those ages 20 to 24 (433.6 per 100,000 men) than other age groups. The overall U.S. rate was 111.6 per 100,000 population.[1]

Results of a nationally representative study show that genital herpes simplex virus type 2 (HSV-2) is common in the United States. Although case report data for this incurable STI are not available, data indicated that 17 percent of people 14- to 49 years of age are infected with HSV-2.[1]

Genital human papillomavirus (HPV) is the most common STI in the United States and, perhaps, the most common STI among sexually active youth. During 2003-2004, nearly a quarter of females aged 15 to 19 years and 45 percent of those aged 20 to 24 had a HPV infection.[2] Among females aged 14 to 24, the overall prevalence of HPV was 34 percent, representing approximately 7.5 million females with HPV in the U.S (higher than the previous estimate of 4.6 million prevalent HPV infections among females 14 to 24 in the U.S.).[3]

Rates of Curable STIs in the United States Are Higher than in Other Developed Nations; ; developing nations beaR most of the bURden

Experts estimate that almost half of the U.S.’s over 19 million STI infections each year occur in youth ages 15-24.4 A recent study found that one in four young women ages 15-19 has an STI in the U.S.[5]

More than 340 million new cases of curable STIs (gonorrhea, chlamydia, syphilis, and trichomonas) occur throughout the world each year, with the majority occurring in low and middle income countries in Latin America, Sub-Saharan Africa, and Southeast Asia.[6]

Globally, adolescents and young adults under 25 have the highest rates of curable STIs. Each year, one in every 20 adolescents and young adults will develop a new STI.[6]

Prevalence of gonorrhea and syphilis is increasing among some populations in Europe, heightening fears that people are being less careful about risky sexual behaviors.[7]

In the United States, Some Populations Are at Disproportionate Risk of STIs.

In 2008, the chlamydia rate among African American/black women ages 15 to 19 was nearly seven times higher than among white females (10,513.4 and 1,534.5 per 100,000 females, respectively). In the same year, the chlamydia rate among American Indian/Alaskan Native (three times higher) and Latina/Hispanic (two times higher) women ages 15 to 19 were also higher than among white females (4,792.6 and 3,186.2 per 100,00 females, respectively). Among black males ages 20 to 24, the chlamydia rate was eight times higher compared to white males (3,825.4 and 465.9 per 100,000 males, respec- tively). Also, in 2008, the chlamydia rate among American Indian/Alaskan Native (nearly three times higher) and Latino/Hispanic (two times higher) were higher compared to their white male peers (1,299.2 and 1,024.4 per 100,000 males, respectively).[1]

In 2008, 71 percent of all reported cases of gonorrhea occurred among blacks. Their gon- orrhea rate was 625 per 100,000 population compared to 110.2 among American Indians/ Alaskan Natives, 66.8 among Latinos/Hispanics, and 31 among whites. The gonorrhea rate among black women ages 15 to 19 was 16 times higher than among white females (2,934.6 and 181.3 per 100,000 females, respectively); among black males ages 15 to 19, the gonorrhea rate was nearly 41 times higher than among white males (1,488 and 36 per 100,000 males, respectively). Among women and men aged 20 to 24, the gonorrhea rate among blacks was 17.1 times greater than among whites (2,556.0 and 149.1 cases per 100,000 populations, respectively).[1]

HPV-16 and HPV-18 account for approximately 70 percent of cervical cancers worldwide. HPV-6 and HPV-11 account for more than 90 percent of cases of genital warts. In a nationally representative study, the seroprevalence of the four HPV types increased from 9 percent among females aged 14 to 19 to 23 percent among those aged 20 to 24. Among males, the seroprevalence of PHV types, 11, 16, and 18 were each less than one percent among those 14 to 19 and 20 to 24. However, seroprevalence for HPV-6 increased from less than one percent among males 14 to 19 to three percent among males 20 to 24. The seroprevalence of four types of HPV was higher among non-Hispanic blacks (47 percent) compared with non-Hispanic whites (32 percent) and Mexican Americans (23 percent).[8]

Chlamydia occurred among 14 percent of females and six percent of males in juvenile facil- ities. Non-Hispanic females and males had the highest chlamydia prevalence, 18 percent and 10 percent respectively.[9]

In one study, self reported viral STIs were sig- nificantly higher among bisexual women (15 to 17.2 percent) than among lesbians (2.3 percent to 6.7 percent).[13]

Factors beyond the Control of Youth May Place Them at Excess Risk for STI.

Young women and female adolescents are more susceptible to STI, compared to their male counterparts, due to their anatomy. During adolescence and young adulthood, women’s columnar epithelial cells—which are especially sensitive to invasion by sexually transmitted organisms, such as chlamydia and gonococcus—extend out over the vaginal surface of the cervix, where they are unprotected by cervical mucous, but recede to a more protected location as women age.[1,14]

STIs are more likely to remain undetected in women than in men, resulting in delayed diagnosis and treatment, and untreated STIs are more likely to lead to complications in women, such as pelvic inflammatory disease and cervical cancer.[1,14]

Poverty and other socioeconomic factors contribute to STI risk. Youth living in poverty may not perceive the risk of STIs or may not practice preventive behaviors if other risks—such as hunger or homelessness—appear more imminent and threatening.[8]

Cultural traditions that value women’s passivity and subordination also diminish the ability of many women to adequately protect themselves, to refuse unwanted sex, and to negotiate condom use.[16]

Dating violence and sexual assault play a role in STI transmission. Twenty percent of U.S. youth report experiencing dating violence. Women who experience dating violence are less likely to use condoms and feel more uncomfortable negotiating condom use. In one study, half of girls who reported HIV or STIs had been physically or sexually abused.[17,18,19,20]

Estimates of the number of runaway and homeless adolescents and young adults in the United States vary from hundreds of thousands to millions. Youth living on the street—many of them lesbian, gay, bisexual, and transgender— are at risk for STIs, as they often engage in survival sex (trading sex for food, shelter, or money), use substances, and frequently suffer sexual and physical assault.[21]

5. Centers for Disease Control and Prevention. Oral Abstract D4a – Prevalence of Sexually Transmitted Infections and Bacterial Vaginosis among Female Adolescents in the United States: Data from the National Health and Nutritional Examination Survey (NHANES) 2003-2004. 2008 National STD Prevention Conference. Accessed from http://www.cdc.gov/stdconference/2008/press/summaries-11march2008.htm#tues1 on 4/27/10

6. Department of Reproductive Health and Research.Global strategy for the prevention and control of sexually transmitted infections: 2006 - 2015. Breaking the chain of transmission. World Health Organization, 2007.

11. Centers for Disease Control and Prevention. Abstract – Calculating HIV and Syphilis Rates for Risk Groups: Estimating the National Population Size of Men Who Have Sex With Men. 2010 National STD Prevention Conference. Accessed from http://cdc.gov/hiv/topics/msm/resources/ research/msm.htm on 4/30/10.